The generation of different mRNAs by varying the pattern of pre-mRNA splicing.
bacterial artificial chromosome (BAC)
A type of vector used for cloning large fragments of DNA in bacteria.
bioinformatics
The use of computational methods to analyze large amounts of biological data, such as genome sequences.
CENP-A
See centromeric H3.
centromere
A specialized chromosomal region that connects sister chromatids and attaches them to the mitotic spindle.
centromeric H3 (CenH3)
A variant of histone H3 that is present at centromeres.
chromatin
The fibrous complex of eukaryotic DNA and histone proteins.
chromatosome
A chromatin subunit consisting of 166 base pairs of DNA wrapped around a histone core and held in place by a linker histone.
DNA transposon
A transposable element that moves via a DNA intermediate.
epigenetic inheritance
The transmission of information that is not contained within the sequence of DNA.
euchromatin
Decondensed, transcriptionally active interphase chromatin.
exon
A segment of a gene that is included in a spliced mRNA.
fluorescence in situ hybridization (FISH)
A method used to localize genes on chromosomes or RNAs within cells using fluorescent probes.
gene
A segment of DNA that encodes a polypeptide chain or an RNA molecule.
gene family
A group of related genes that have arisen by duplication of a common ancestor.
genome-wide association scan
A method of large-scale genome analysis used to identify genes responsible for inherited diseases.
heterochromatin
Condensed, transcriptionally inactive chromatin.
histone
Member of a family of proteins that package DNA in eukaryotic chromosomes.
intron
A noncoding sequence that interrupts exons in a gene.
kilobase (kb)
One thousand nucleotides or nucleotide base pairs.
kinetochore
A specialized structure consisting of proteins attached to a centromere that mediates the attachment and movement of chromosomes along the mitotic spindle.
LINE (long interspersed element)
Member of a family of highly repeated retrotransposons in mammalian genomes.
megabase (Mb)
One million nucleotides or nucleotide base pairs.
nucleosome
The basic structural unit of chromatin consisting of DNA wrapped around a histone core.
nucleosome core particle
Particle containing 146 base pairs of DNA wrapped around an octamer consisting of two molecules each of histones H2A, H2B, H3, and H4.
open-reading frame
A stretch of nucleotide sequence that does not contain stop codons and can encode a polypeptide.
polytene chromosome
A giant chromosome found in some tissues of Drosophila that arises from repeated replication of DNA strands that fail to separate from each other.
processed pseudogene
A pseudogene that has arisen by reverse transcription of mRNA.
pseudogene
A nonfunctional gene copy.
retrotransposon
A transposable element that moves via reverse transcription of an RNA intermediate.
retrovirus-like element
A retrotransposon that is structurally similar to a retrovirus.
RNA splicing
The joining of exons in a precursor RNA molecule.
satellite DNA
Simple-sequence repetitive DNA with a buoyant density differing from the bulk of genomic DNA.
simple-sequence repeat
Member of a class of repeated DNA sequences consisting of tandem arrays of thousands of copies of short sequences.
SINE (short interspersed element)
Member of a family of highly repeated retrotransposons in mammalian genomes.
spacer sequence
A DNA sequence between genes.
systems biology
A new field of biology in which large-scale experimental approaches are combined with quantitative analysis and modeling to study complex biological systems.
telomerase
A reverse transcriptase that synthesizes telomeric repeat sequences at the ends of chromosomes from its own RNA template.
telomere
A repeat of simple-sequence DNA that maintains the ends of linear chromosomes.
yeast artificial chromosome (YAC)
A vector that can replicate as a chromosome in yeast cells and can accomodate very large DNA inserts (hundreds of kb).
